Abstract: Quaternary history of lakes, loess, deserts, Vegetation and paleo-fauna ete. makes known that arid environment in the North-West of china was begun at middle stage of Quaternary period (1.4-1.2 M. Y. B. P), was not begun from last stage on Tertiary pcriod to early stage of Quaternary period. The cause lie in young and guicking quality of the uplift of the Qinghai-Xizang Plateau and high mauntains in the North-West of China.